In a sterilization method, use of ozone (O3) having high oxidation power is conventionally known.
Conventionally known examples of the production method may include a production method through electrical discharge and a production method through a photochemical reaction. In the method through electrical discharge, silent discharge such as creeping discharge is caused in an oxygen (O2)-containing gas atmosphere to produce ozone. In the method through a photochemical reaction, an oxygen-containing gas is irradiated with an ultraviolet ray to produce ozone.
In the sterilization method, the production method of ozone through electrical discharge is widely used.
As a sterilization method using ozone, Patent Literature 1 discloses a technique in which an object to be sterilized which exists in an air constituting an atmosphere of a room or is attached to a surface of an object arranged in a room is exposed to a mixture of an ozone-containing air and a mist (moisture), subjecting the air constituting the atmosphere or the arranged object to a sterilization treatment.
In the sterilization method described in Patent Literature 1, the air constituting the atmosphere of the room is taken into a duct, and creeping discharge is caused in the duct to produce ozone. Then, an ozone-containing air which contains the produced ozone is mixed with a mist (moisture) which is discharged from an atomizing nozzle. Subsequently, a mixture of the ozone-containing air and the mist is supplied to the room from the duct. Asa result, the air constituting the atmosphere of the room and the arranged object in the room are subjected to a sterilization treatment. In this sterilization method, it is considered preferable that the humidity in the room where the mixture of the air containing ozone and the mist is supplied, that is, the humidity in the room where the sterilization treatment is performed is high, for example, not lower than 80% from the viewpoint of sterilization efficiency.
As described above, it is conventionally known that the sterilization efficiency in the sterilization method using ozone depends on an atmosphere in a space where an object to be sterilized is sterilized (a space in a room where the sterilization treatment is performed). However, it is not clear as to how a production method of ozone for use in the sterilization treatment affects the sterilization efficiency. A relationship between the production method of ozone and the sterilization efficiency has not been conventionally taken into consideration in the sterilization method using ozone.